package cn.ffcs.uec.view.util;

import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Cipher;

public class RSAUtils
{
  private static final String DEFAULT_CHARSET_NAME = "UTF-8";
  public static final String KEY_ALGORITHM = "RSA";
  public static final String TRANSFORMATION_NAME = "RSA/ECB/PKCS1Padding";
  public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
  private static final String PUBLIC_KEY = "RSAPublicKey";
  private static final String PRIVATE_KEY = "RSAPrivateKey";
  private static final int MAX_ENCRYPT_BLOCK = 117;
  private static final int MAX_DECRYPT_BLOCK = 128;
  
  public static Map<String, Object> genKeyPair()
    throws Exception
  {
    KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
    
    keyPairGen.initialize(1024);
    KeyPair keyPair = keyPairGen.generateKeyPair();
    RSAPublicKey publicKey = (RSAPublicKey)keyPair.getPublic();
    RSAPrivateKey privateKey = (RSAPrivateKey)keyPair.getPrivate();
    Map<String, Object> keyMap = new HashMap(2);
    keyMap.put("RSAPublicKey", publicKey);
    keyMap.put("RSAPrivateKey", privateKey);
    return keyMap;
  }
  
  public static String sign(byte[] data, String privateKey)
    throws Exception
  {
    byte[] keyBytes = Base64Utils.decode(privateKey);
    PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
    Signature signature = Signature.getInstance("MD5withRSA");
    signature.initSign(privateK);
    signature.update(data);
    return Base64Utils.encode(signature.sign());
  }
  
  public static boolean verify(byte[] data, String publicKey, String sign)
    throws Exception
  {
    byte[] keyBytes = Base64Utils.decode(publicKey);
    X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    PublicKey publicK = keyFactory.generatePublic(keySpec);
    Signature signature = Signature.getInstance("MD5withRSA");
    signature.initVerify(publicK);
    signature.update(data);
    return signature.verify(Base64Utils.decode(sign));
  }
  
  public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)
    throws Exception
  {
    byte[] keyBytes = Base64Utils.decode(privateKey);
    PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
    cipher.init(2, privateK);
    int inputLen = encryptedData.length;
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    int offSet = 0;
    
    int i = 0;
    while (inputLen - offSet > 0)
    {
      byte[] cache;
     // byte[] cache;
      if (inputLen - offSet > 128) {
        cache = cipher.doFinal(encryptedData, offSet, 128);
      } else {
        cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
      }
      int index = -1;
      for (int row = 0; row < cache.length; row++) {
        if (cache[row] == 0)
        {
          index = row;
          break;
        }
      }
      if (index > -1) {
        out.write(cache, index + 1, cache.length - index - 1);
      } else {
        out.write(cache, 0, cache.length);
      }
      i++;
      offSet = i * 128;
    }
    byte[] decryptedData = out.toByteArray();
    out.close();
    return decryptedData;
  }
  
  public static String decryptByPrivateKeyStr(String encryptedDataStr, String privateKey)
    throws Exception
  {
    byte[] encryptedData = HexByteUtil.hexStr2ByteArr(encryptedDataStr);
    
    String str = new String(decryptByPrivateKey(encryptedData, privateKey), "UTF-8");
    return str;
  }
  
  public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)
    throws Exception
  {
    byte[] keyBytes = Base64Utils.decode(publicKey);
    X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    Key publicK = keyFactory.generatePublic(x509KeySpec);
    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
    cipher.init(2, publicK);
    int inputLen = encryptedData.length;
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    int offSet = 0;
    
    int i = 0;
    while (inputLen - offSet > 0)
    {
      byte[] cache;
      //byte[] cache;
      if (inputLen - offSet > 128) {
        cache = cipher.doFinal(encryptedData, offSet, 128);
      } else {
        cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
      }
      out.write(cache, 0, cache.length);
      i++;
      offSet = i * 128;
    }
    byte[] decryptedData = out.toByteArray();
    out.close();
    return decryptedData;
  }
  
  public static String decryptByPublicKeyStr(String encryptedDataStr, String publicKey)
    throws Exception
  {
    byte[] encryptedData = HexByteUtil.hexStr2ByteArr(encryptedDataStr);
    
    String str = new String(decryptByPublicKey(encryptedData, publicKey), "UTF-8");
    return str;
  }
  
  public static byte[] encryptByPublicKey(byte[] data, String publicKey)
    throws Exception
  {
    byte[] keyBytes = Base64Utils.decode(publicKey);
    X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    Key publicK = keyFactory.generatePublic(x509KeySpec);
    
    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
    cipher.init(1, publicK);
    int inputLen = data.length;
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    int offSet = 0;
    
    int i = 0;
    while (inputLen - offSet > 0)
    {
      byte[] cache;
     // byte[] cache;
      if (inputLen - offSet > 117) {
        cache = cipher.doFinal(data, offSet, 117);
      } else {
        cache = cipher.doFinal(data, offSet, inputLen - offSet);
      }
      out.write(cache, 0, cache.length);
      i++;
      offSet = i * 117;
    }
    byte[] encryptedData = out.toByteArray();
    out.close();
    return encryptedData;
  }
  
  public static String encryptByPublicKeyStr(String dataStr, String publicKey)
    throws Exception
  {
    byte[] data = dataStr.getBytes("UTF-8");
    String encryptedDateStr = HexByteUtil.byteArr2HexStr(encryptByPublicKey(data, publicKey));
    
    return encryptedDateStr;
  }
  
  public static byte[] encryptByPrivateKey(byte[] data, String privateKey)
    throws Exception
  {
    byte[] keyBytes = Base64Utils.decode(privateKey);
    PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
    Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
    cipher.init(1, privateK);
    int inputLen = data.length;
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    int offSet = 0;
    
    int i = 0;
    while (inputLen - offSet > 0)
    {
      byte[] cache;
     // byte[] cache;
      if (inputLen - offSet > 117) {
        cache = cipher.doFinal(data, offSet, 117);
      } else {
        cache = cipher.doFinal(data, offSet, inputLen - offSet);
      }
      out.write(cache, 0, cache.length);
      i++;
      offSet = i * 117;
    }
    byte[] encryptedData = out.toByteArray();
    out.close();
    return encryptedData;
  }
  
  public static String encryptByPrivateKeyStr(String dataStr, String privateKey)
    throws Exception
  {
    byte[] data = dataStr.getBytes("UTF-8");
    String encryptedDateStr = HexByteUtil.byteArr2HexStr(encryptByPrivateKey(data, privateKey));
    
    return encryptedDateStr;
  }
  
  public static String getPrivateKey(Map<String, Object> keyMap)
    throws Exception
  {
    Key key = (Key)keyMap.get("RSAPrivateKey");
    return Base64Utils.encode(key.getEncoded());
  }
  
  public static String getPublicKey(Map<String, Object> keyMap)
    throws Exception
  {
    Key key = (Key)keyMap.get("RSAPublicKey");
    return Base64Utils.encode(key.getEncoded());
  }
  
  public static void main(String[] args) throws Exception {
	  String privateKey = "RSAPrivateKey";
	  RSAUtils rSAUtils = new RSAUtils();
	 String aa= rSAUtils.encryptByPrivateKeyStr("123456",privateKey);
	 System.out.println("aa============"+aa);
}
}

